I can answer your questions based on my own personal experience. My story is similar to millions of alcoholics.
Alcoholism is progressive. I could cut back for periods of time, even abstain for periods of time. However, there is an invisible line. Once an alcoholic crosses that line: their entire body, mind and soul is addicted. After the body becomes addicted to alcohol, and moderation is attempted, the addiction is just being incubated. It festers below the surface, thriving and waiting. It is just a matter of time before the volume of alcohol increases or another substance is introduced to feed the addiction and the desire to escape.
Not every alcoholic has to lose everything before they turn their life around. I had reached an emotional bottom when I turned my life around. It is possible your friend will see his condition and stop the cycle before he loses another job.
Now, tell me what you are doing for yourself?
Are you attending Alanon meetings?
Are you learning to keep yourself lovingly detached from the active alcoholic?
You show wisdom and strength in recognizing that your friendship can not develop into a relationship while he is actively addicted to alcohol. Good on you!